Hybrid film-electronic camera having a dynamic number of stored electronic images protected from overwriting and method

ABSTRACT

In a hybrid camera and method, the number of stored electronic images protected from overwriting is not fixed, but instead changes depending upon the film unit used in the camera. In the method, a first film unit is loaded in the camera. The first film unit has a first quantity of available film frames. An equal quantity of corresponding electronic images is less than the capacity of memory in the camera. The first quantity is determined by the camera and a tag number is set to an integer value equal to or less than the difference between the image capacity, in units of space for individual ones of the electronic images, and the first quantity. A plurality of electronic images are captured in the camera and stored in the memory. Individual tags are selectively assigned to one or more of the electronic images. The first film unit is removed and a second film unit is loaded in the camera. The second film unit has a second quantity of available film frames that is less than the image capacity. The second quantity is determined. The tag number is then reset to an integer value that is equal to or less than the difference between the image capacity and the second quantity. A warning is displayed when the tag number is less than the number of tagged images.

CROSS REFERENCE TO RELATED APPLICATIONS

Reference is made to commonly assigned, co-pending U.S. patentapplications Ser. No. 10/022,491, entitled: CAMERA HAVING SELECTIVEIMAGE EXCLUSION FROM FIRST IN-FIRST OUT ELECTRONIC IMAGE OVERWRITING ANDMETHOD, filed 18 Dec. 2001 in the name of Stephen G. Malloy Desormeaux,which is a Continuation-In-Part application of Ser. No. 09/945,946,entitled: CAMERA HAVING SELECTIVE IMAGE EXCLUSION FROM FIRST IN-FIRSTOUT ELECTRONIC IMAGE OVERWRITING AND METHOD, filed 04 Sep. 2001, in thename of Stephen G. Malloy Desormeaux, now abandoned; Ser. No.09/945,989, entitled: CAMERA HAVING SINGLE-BUTTON TIMED DISPLAY OFMOST-RECENTLY VIEWED IMAGE AND DEFAULT DISPLAY OF LAST VERIFICATIONIMAGE AND METHOD, filed 04 Sep. 2001, in the name of Stephen G. MalloyDesormeaux, Ser. No. 09/946,051, entitled: CAMERA THAT DOWNLOADSELECTRONIC IMAGES HAVING METADATA IDENTIFYING IMAGES PREVIOUSLY EXCLUDEDFROM FIRST IN-FIRST OUT OVERWRITING AND METHOD, filed 04 Sep. 2001, inthe names of Nathan J. Romano and Stephen G. Malloy Desormeaux; and Ser.No. 09/946,098, entitled CAMERA HAVING ELECTRONIC IMAGES CORRESPONDINGTO CURRENT FILM IMAGES AUTOMATICALLY EXCLUDED FROM FIRST IN-FIRST OUTOVERWRITING AND METHOD, filed 04 Sep. 2001, in the names of Stephen G.Malloy Desormeaux and Robert Hills.

FIELD OF THE INVENTION

The invention relates to photography and photographic equipment and moreparticularly relates to hybrid film-electronic cameras and methods inwhich a dynamic number of stored electronic images are protected fromoverwriting.

BACKGROUND OF THE INVENTION

Hybrid electronic-film cameras allow photographers to capture sceneimages (the light images of particular scenes) as latent images onphotographic film and as electronic images that are digitized and storedin memory. The electronic images are retained in the memory until beingoverwritten or being removed, such as by withdrawal of a removablememory unit. The electronic images are made available for use bydownloading into a computer or other device. The photographer isgenerally allowed to view electronic images in the memory of the camera.The issue is, how should that memory be managed in attempting to meetthe photographer's needs and expectations.

One of the problems is that the available space for latent images in afilm unit and electronic images in memory can be the same; but this isnot generally the case. One of the reasons is that the camera canaccommodate film units having different numbers of film frames and thememory is fixed in size or is subject to change in a different manner.Another reason in some hybrid cameras, is that the camera can captureboth electronic images that correspond to concurrently captured filmimages and electronic images that are captured without any concurrentfilm image. In most cases, thus, there is a disparity between the numberof latent images in a film unit in the camera and the number ofelectronic images currently in the memory of the camera.

It is straightforward that photographers would like to be able to reviewevery electronic image in camera memory corresponding to a latent imagein a film unit currently present in the camera. It is not sostraightforward how to handle electronic images in the memory of thecamera that can do not correspond to latent image images in the filmunit in the camera. Those electronic images can have been capturedwithout a corresponding film image or can be electronic images thatcorrespond to a latent image in an earlier film unit that has since beenunloaded from the camera.

In his currently impractical to supply so much memory in a hybrid camerathat all electronic images that a photographer is likely to have aninterest in reviewing indefinitely remain available for the photographerto review. Thus, some electronic images in the memory must beoverwritten during use. This overwriting can be done on a first in-firstout (FIFO) basis. This approach does not take into account the fact thatmemory needed for review of electronic images corresponding to filmimages in a film unit in the camera is not static. This approach weightsall electronic images equally and does not take into account anypossibility of the photographer having different levels of interest indifferent electronic images. For example, the photographer may want todownload some electronic images for later use and may intend to neveruse others of the electronic images.

It would thus be desirable to provide improved cameras and methods inwhich memory available for electronic images is dynamically adjusted.

SUMMARY OF THE INVENTION

The invention is defined by the claims. The invention, in its broaderaspects, provides a hybrid camera and method, in which the number ofstored electronic images protected from overwriting is not fixed, butinstead changes depending upon the film unit used in the camera. In themethod, a first film unit is loaded in the camera. The first film unithas a first quantity of available film frames. An equal quantity ofcorresponding electronic images is less than the capacity of memory inthe camera. The first quantity is determined by the camera and a tagnumber is set to an integer value equal to or less than the differencebetween the image capacity, in units of space for individual ones of theelectronic images, and the first quantity. A plurality of electronicimages are captured in the camera and stored in the memory. Individualtags are selectively assigned to one or more of the electronic images.The first film unit is removed and a second film unit is loaded in thecamera. The second film unit has a second quantity of available filmframes that is less than the image capacity. The second quantity isdetermined. The tag number is then reset to an integer value that isequal to or less than the difference between the image capacity and thesecond quantity. A warning is displayed when the tag number is less thanthe number of tagged images.

It is an advantageous effect of the invention that improved cameras andmethods are provided in which memory available for electronic imagesprotected from first in-first out overwriting is dynamically adjusted.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and objects of this invention andthe manner of attaining them will become more apparent and the inventionitself will be better understood by reference to the followingdescription of an embodiment of the invention taken in conjunction withthe accompanying figures wherein:

FIG. 1 is a diagrammatical view of the camera and system.

FIGS. 2-2B present a schematic diagram of an embodiment of the camera.

FIG. 3 is a perspective view of the camera of FIG. 2.

FIG. 4 is an exploded perspective view of the camera of FIG. 2.

FIG. 5 is a diagram of the method for selectively excluding images fromfirst in-first out electronic image overwriting. Time extends along thex-axis from left to right. Units are arbitrary and steps are cut-off atthe right end of the diagram. Each step of the method takes place withinthe indicated block of time, but not necessarily for the entire block oftime.

FIG. 6 is a flow chart of the method for maintaining a dynamic number ofstored electronic images protected from overwriting.

FIG. 7 is a semi-diagrammatical rear plan view of another embodiment ofthe camera, showing an untagged verification image. The camera has oneor more tags available.

FIG. 8 is the same view as in FIG. 7, but shows a tagged image.

FIG. 9 is the same view as in FIG. 7 and shows an untagged image, butthe camera has no available tags.

FIG. 10 is the same view as in FIG. 7, but the displays show a warningthat tagged images will be overwritten if capture of images is continuedwithout downloading or untagging images.

FIG. 11 is a front view of the monitor of the computer of FIG. 1 showingfour downloaded images, two of which are tagged.

FIG. 12 is a diagrammatical view of one of the downloaded images shownin FIG. 11. In a particular embodiment, FIG. 12 also illustrates anelectronic image within the camera of FIG. 1.

FIGS. 13-16 are diagrammatical views illustrating the replacement orderin a modified camera and method. Each of FIGS. 13-16 shows the effect ofthis replacement order on a different sequence of capture events. Rowsa-f in each of FIGS. 13-16 illustrate captured images present in thecamera, following each capture event of a sequence. Film images aredepicted by a film frame shown in solid lines. Electronic images bydashed line boxes. Vertically adjoining film images and electronicimages correspond to the same scene image. “X” represents an electronicimage that has been replaced. Within each row, an empty space below anelectronic image indicates that no corresponding film image is presentin the camera.

FIG. 17 is a schematic diagram of an embodiment of the camera of FIGS.13-16.

FIG. 18 is a semi-diagrammatical rear plan view of the camera of FIG. 17showing a retained image on the image display.

FIG. 19 is the same view as FIG. 18, but shows a non-retained image onthe image display.

DETAILED DESCRIPTION OF THE INVENTION

In the following, feature sets of the several different cameras andmethods are discussed in terms of particular embodiments combining allor many of those features. Alternative embodiments combining fewerfeatures and alternative features are also discussed herein. Otheralternatives will be apparent to those of skill in the art.

The cameras 10 herein each provide both an archival image of a scene andan evaluation image of the same scene. The archival image and theevaluation image are captured concurrently. The archival image is laterused in photofinishing, or printing, or other long term or relativelylong term use. The evaluation image is immediately available for displayand review by the user.

Some of the cameras 10 discussed herein have embodiments with a singleelectronic imager that is used to capture a scene image as an initialelectronic image. Both an archival image and an evaluation image aregenerated from the initial electronic image. The evaluation image can besubsampled from an original electronic image so as to provide lowerresolution derived images. The lower resolution derived images can beprovided using the method described in commonly-assigned U.S. Pat. No.5,164,831, entitled “ELECTRONIC STILL CAMERA PROVIDING MULTI-FORMATSTORAGE OF FULL AND REDUCED RESOLUTION IMAGES”, to Kuchta, et. al.

In currently preferred embodiments, the cameras 10 have a capture system12 that has an archival image capture unit 14 and a separate evaluationimage capture unit 16. The two different capture units 14,16 can take avariety of forms and can be completely separate from each other or canshare some components. The evaluation image capture unit 16 captures ascene image electronically and can also be referred to as an electronicimage capture unit 16. The archival image capture unit 14 captures andstores images in a film unit 18.

The term “film unit 18” is used herein to refer to media 20 on whichimage data is or can be stored for archival purposes, with or withoutmedia modification, and physically associated features supporting use ofthe media. Each film unit 18 stores or can store a plurality of archivalimages. In a film-type film unit 18, the media 20 is a photographicfilmstrip 20 a. The support structure 22 of a film-type film unit 18 agenerally provides light blocking and, for example, can include a spool22 a on which the filmstrip 20 a is wound and canister 22 b enclosingthe filmstrip 20 a and spool 22 a. In an electronic-type film unit 18the media 20 is removable digital storage media 20 b. With digitalstorage media 20 b, archival images are transferred in digital form forphotofinishing, printing, or other use. A digital film unit 18, like aphotographic film unit 18 is removable from the camera 10. The type ofdigital media used and the manner of information storage, such asoptical or magnetic or electronic, is not critical. For example, adigital film unit can be a floppy disc, a CD, a DVD, a tape cassette, orflash memory card or stick.

The evaluation image capture unit 16 captures electronic images. Thearchival image capture unit 14 can be a photographic film image captureunit 14 a that captures images on photographic film. Alternatively, thearchival image capture unit 14 and evaluation image capture unit 16 canbe two different electronic capture units. An example of a suitabledigital camera having two such electronic capture units is described inU.S. Pat. No. 5,926,218, entitled “ELECTRONIC CAMERA 10 WITH DUALRESOLUTION SENSORS”, to Smith. The camera 10 can also alternativelyallow use of either a film image capture unit 14 a or an electroniccapture unit as the archival image capture unit 14, at the selection ofthe photographer or on the basis of available storage space in one oranother capture media or on some other basis. For example, a switch (notseparately illustrated) can provide alternative film capture andelectronic capture modes.

The invention is generally discussed herein in terms of film units 18 athat use photographic film for storage of archival images as latentimages and, optionally, store some additional information in the filmunit 18, magnetically, optically, or both. It will be understood thatequivalent considerations apply to other types of film units 18. Forexample, units of digital memory for individual archival imagescorrespond to film frames (discussed in detail below).

Camera 10 features disclosed herein are particularly advantageous forhybrid cameras 10 having archival image units 14 that capture imagesusing photographic film-type film units 18 as archival media 18 and alsohaving electronic image units 16 that capture the evaluation images.This is not limiting. Advantages of specific embodiments will be readilyapparent by simple experimentation implementing the particular features.

Referring now particularly to FIGS. 1-4, the camera 10 has a body 24that holds a capture system 12 having an archival image capture unit 14that uses photographic film 20 a and an evaluation image capture unit 16that captures images electronically. When the photographer trips ashutter release 26, a subject image (a light image of a scene) iscaptured as a latent image on a frame 28 of the film 20 a and at leastone electronic image is captured on an electronic array imager 30 of theevaluation image capture unit 16. The electronic image or images aredigitally processed and used to provide one or more derived images thatcan be shown on an image display 32 mounted to the body 24.

The electronic images, as captured in analog form and afterdigitization, but not other modification, are referred to genericallyherein as “original electronic images”. After further modification, theelectronic images are referred to generically herein by the term“derived images”. Derived images are modified relative to the originalimages. This can be for calibration to the display or a particular filestructure, or matching to output media. These modifications may or maynot also include the addition of metadata to the electronic image file.A derived image that is matched to the expected product ofphotofinishing the archival image is also referred to herein as a“verification image”. More than one derived image can be made from asingle original electronic image. A derived image that differs from theverification image in a predetermined manner, unrelated to expectedphotofinishing, is referred to herein as an “evaluation image”.Modifications matched to expected photofinishing or other downstreamuse, may or may not also be present in an evaluation image.

A control system 34 that includes a controller 36 (also referred toherein as a microcomputer) and can also include a digital signalprocessor 38, controls other components of the camera 10 and performsprocessing related to the derived image.

The camera body 24 provides structural support and protection for thecapture units 14,16 and other components. The body 24 of the camera 10can be varied to meet requirements of a particular use and styleconsiderations. It is convenient, if the body 24 has front and rearcovers 40,42 joined together over a chassis 44. Many of the componentsof the camera 10 can be mounted to the chassis 44.

A film door 46 and a flip-up electronic flash unit 48 are pivotablyjoined to the covers 40,42 and chassis 44. The flash unit 48 is flippedup from partially covering the front cover 40 to uncover the taking lens50, preparatory to using the camera 10. Flipping up the flash unit 48closes a normally open main power switch 51 to electrically power on thecamera 10. The type of main power switch 51 used and its manner ofoperation can be varied as desired. A power supply 53 accessed throughthe main power switch 51 is ordinarily one or more batteries.

The film image capture unit 14 has a film holder 52 that holds a filmunit 18 during use. In the camera 10 of FIGS. 3-4, the film holder 52 ispart of the chassis 44. The configuration of the film holder 52 is afunction of the type of film unit 18 used and is not otherwisesignificant.

The film holder 52 includes a pair of film chambers 54,56 and arearwardly opening exposure frame 58 between the film chambers 54,56.The film unit 18 has a canister 22 b disposed in one of the chambers54,56. A filmstrip 20 a is wound around a spool 22 a held by thecanister 22 b. During use, the filmstrip 20 a extends across theexposure frame 58 and is wound into a film roll 60 in the other chamber56. The exposure frame 58 has an opening 62 through which a light imageexposes a frame 28 of the film at each picture taking event.

During use, the filmstrip 20 a is moved by a film transport 64 out ofthe canister 22 b of the film unit, is wound into a film roll 60 in thesupply chamber 56, and is then returned to the canister 22 b. The filmtransport 64, as illustrated, includes an electric motor 66 locatedwithin a film roll spool 68, but other types of motorized transportmechanisms and manual transports can also be used. Filmstrip exposurecan be on film advance or on rewind.

The camera 10 shown in FIGS. 3-4 is reloadable and has motorized filmtransport. The camera 10 uses an Advanced Photo System (“APS”) filmcartridge. Other types of one or two chamber film cartridge could alsobe used and roll film can also be used. It is currently preferred thatthe camera 10 is reloadable. The camera 10 can have a IX-DX code reader67 to determine the film type and number of film frames.

The APS filmstrip 20 a has a transparent magnetic overlay (notillustrated) which gives it a magnetic recording capacity to storevarious metadata such as number of prints ordered and print aspectratio, along a magnetic information track adjacent each exposed filmframe 28. The filmstrip 20 a is normally housed in an opaque filmcartridge and is typically available in 15-exposure, 25-exposure, and40-exposure lengths. Metadata, including user-selected information, candiffer from frame-to-frame. The camera 10 has a data recorder 70positioned adjoining the filmstrip 20 a to record the metadata. FIGS.3-4 illustrate an APS camera 10 with a data recorder 70 in the form of amagnetic head mounted within an opening in a film pressure platen 72 formagnetically recording the metadata along the magnetic information trackadjacent each one of the exposed film frames 28, when the exposed filmlength is advanced out of the film cartridge. The film pressure platen72 serves to support each film frame 28 flat for exposure at theexposure frame 58.

The cameras 10 herein are not limited to APS film units nor to recordingmetadata on a magnetic layer. Optical recording of metadata by camerasis well known in the art, as are other means of storing such informationsuch as use of memory media attached to a film canister. Informationincluding the kinds of metadata provided by APS cameras and films, canbe written, or read, or both by any means well known to those of skillin the art.

Frames 28 of the filmstrip 20 a are temporarily positioned, one at atime, in the exposure frame 58, for archival image exposure. The filmroll spool is incrementally rotated following each film frame exposure,to wind the most-recently exposed one of the film frames 28 onto anexposed film roll 60 on the spool 68 and to position a fresh unexposedfilm frame 28 at the exposure frame 58. When the film roll spool 68 isincrementally rotated by the film transport 64, the filmstrip 20 a isadvanced forward one frame increment (which is slightly greater than aframe width) from the film cartridge. Film transport is controlled bythe controller 36. When substantially the entire length of the filmstrip20 a is exposed, i.e. the total number of available frames 28 areexposed, a spindle (not shown) which projects into a cavity in a top endof a film spool 22 a inside the film cartridge is continuously rotatedby the film drive 64 using a suitable gear train (not shown) to rewindthe exposed film length rearward into the film cartridge.

To magnetically record user-selected information as metadata on thefilmstrip 20 a, the magnetic track or tracks on the filmstrip 20 a aremoved past the data recorder 70 at an appropriate speed while a field isgenerated in a recording head (not shown) of the recorder 70. Therecording can be done stepwise, moving the filmstrip 20 a in incrementsfor each film frame 28 or the data can be stored in memory in the camera10 until all film exposures are completed, then all the data can berecorded in a single continuous pass. When all film exposures arecompleted and metadata has been recorded and the filmstrip 20 a islight-tightly closed in the film canister 22 b, the film unit 18 can beremoved from the camera 10 by opening the film door 46.

The electronic image capture unit 16 has an electronic array imager 30driven by an imager driver 74. The electronic array imager 30 isconfigured so as to capture, for each picture-taking event, one or moreelectronic images that correspond to a latent image concurrentlycaptured on the filmstrip 20 a. The type of imager 30 used may vary, butit is highly preferred that the imager 30 be one of the severalsolid-state imagers available.

One highly popular type of solid-state imager commonly used is thecharge coupled device (“CCD”). Of the several CCD types available, twoallow easy electronic shuttering and thereby are preferable in this use.The first of these, the frame transfer CCD, allows charge generation dueto photoactivity and then shifts all of the image charge into a lightshielded, non-photosensitive area. This area is then clocked out toprovide a sampled electronic image. The second type, the interlinetransfer CCD, also performs shuttering by shifting the charge, butshifts charge to an area above or below each image line so that thereare as many storage areas as there are imaging lines. The storage linesare then shifted out in an appropriate manner. Each of these CCD imagerhas both advantages and disadvantages, but all will work in thisapplication. A typical CCD has separate components that act as clockdrivers, analog signal processor-analog/digital converter (also referredto as “A/D converter 114”).

It is also possible to use an electronic image sensor manufactured withCMOS technology. This type of imager is attractive for use, since it ismanufactured easily in a readily available solid-state process and lendsitself to use with a single power supply. In addition, the processallows peripheral circuitry to be integrated onto the same semiconductordie. For example, a CMOS sensor can include clock drivers, the A/Dconverter 114, and other components integrated on a single IC. A thirdtype of sensor which can be used is a charge injection device (CID).This sensor differs from the others mentioned in that the charge is notshifted out of the device to be read. Reading is accomplished byshifting charge within the pixel. This allows a nondestructive read ofany pixel in the array. If the device is externally shuttered, the arraycan be read repeatedly without destroying the image. Shuttering can beaccomplished by external shutter or, without an external shutter, byinjecting the charge into the substrate for recombination.

The electronic image capture unit 16 captures a three-color image. It ishighly preferred that a single imager be used along with a three-coloror four color filter, however, multiple monochromatic imagers andfilters can be used. Suitable three-color filters are well known tothose of skill in the art, and are normally incorporated with the imagerto provide an integral component. For convenience, the camera 10 isgenerally discussed herein in relation to embodiments having a singleimager 30 with a three color filter (not separately illustrated). Itwill be understood that like considerations apply to cameras using morethan three colors as well as cameras using multiple monochromaticimagers.

Referring now primarily to FIG. 2, the camera 10 has a optical system 76of one or more lenses mounted in the body 24. The optical system 76 isillustrated by a dashed line and several groups of lens elements. Itwill be understood that this is illustrative, not limiting. The opticalsystem 76 directs light to the exposure frame 58 and to the electronicarray imager 30. The optical system 76 also preferably directs lightthrough an optical viewfinder 78 to the user.

The imager 30 is spaced from the exposure frame 58, thus, the opticalsystem 76 directs light along a first path (indicated by a dotted line80) to the exposure frame 58 and along a second path (indicated by adotted line 82) to the electronic array imager 30. Both paths 80,82converge at a position in front of the camera 10, at the plane of thesubject image. In FIG. 2, the optical system 76 has a combined lens unit84 that includes both an imager lens unit 86 and a viewfinder lens unit88. The combined lens unit 84 has a partially transmissive mirror 90that subdivides the second light path 82 between an imager subpath tothe imager 30 and a viewfinder subpath that is redirected by a fullyreflective mirror 92 and transmitted through an eyepiece to thephotographer.

The optical system 76 can be varied. For example, the viewfinder lensunit 88, imager lens unit 86, and a taking lens unit 50 can be fullyseparate (not shown) or a combined lens unit 84 can include both ataking lens unit 50 and an imager lens unit 86 (not shown). Otheralternative optical systems can also be provided.

In most cameras 10, there is a variation between the field of view ofthe viewfinder 78 and the field of view of the archival image captureunit 14. The scene delineated by the viewfinder 78 is typically 80 to 95percent of the field of view of the archival image capture unit 14. Thedifference ensures that everything the photographer sees will becaptured in the archival image, albeit with some additional imagecontent at the edges. Cameras 10 are generally described and illustratedherein in terms of viewfinders that have a 100 percent match to thefield of view of the archival image capture unit. This is a matter ofconvenience in describing the invention. The viewfinders 78 of thecameras 10 can be limited to 80 to 95 percent of the field of view ofthe archival image capture unit 14 without changing the other featuresdescribed.

Referring again to the embodiment shown in FIG. 2, the taking lens unit50 is a motorized zoom lens in which a mobile element or elements aredriven, relative to a stationary element or elements, by a zoom driver94. The combined lens unit 84 also has a mobile element or elements,driven, relative to a stationary element or elements, by a zoom driver94. The different zoom drivers 94 are coupled so as to zoom together,either mechanically (not shown) or by a control system 34 signaling thezoom drivers 94 to move the zoom elements of the units over the same orcomparable ranges of focal lengths at the same time.

The control system 34, which includes a controller 36, can take the formof an appropriately configured microcomputer, such as an embeddedmicroprocessor having RAM or other memory for data manipulation andgeneral program execution.

The taking lens unit 50 of the embodiment of FIG. 2 is alsoautofocusing. An autofocusing system has a rangefinder 96 that includesa sensor 98. The rangefinder 96 operates a focus driver 100, directly orthrough the control system 34, to move one or more focusable elements(not separately illustrated) of the taking lens unit 50. The rangefinder96 can be passive or active or a combination of the two.

The taking lens unit 50 can be simple, such as having a single focallength and manual focusing or a fixed focus, but this is not preferred.One or both of the viewfinder lens unit 88 and imager lens unit 86 canhave a fixed focal length or one or both can zoom between differentfocal lengths. Digital zooming (enlargement of a digital imageequivalent to optical zooming) can also be used instead of or incombination with optical zooming for the imager 30. The imager 30 andimage display 32 can be used as a viewfinder 78 prior to image capturein place of or in combination with the optical viewfinder 78, as iscommonly done with digital still cameras 10. This approach is notcurrently preferred, since battery usage is greatly increased.

Although the camera 10 can be used in other manners, the archival imageis intended to provide the basis of the photofinished or other finalimage desired by the user. The derived images thus do not have to havethe same quality as the archival image. As a result, the imager 30 andthe portion of the optical system 76 directing light to the imager 30can be made smaller, simpler, and lighter. For example, the taking lensunit can be focusable and the imager lens unit 86 can have a fixed focusor can focus over a different range or between a smaller number of focuspositions.

A film shutter 102 shutters 102,104 the light path to the exposure frame58. An imager shutter 104 shutters 102,104 the light path to the imager30. Diaphragms/aperture plates 106 can also be provided in both of thepaths 80,82. Each of the shutters 102,104 is switchable between an openstate and a closed state. The term “shutter” is used in a broad sense torefer to physical and/or logical elements that provide the function ofallowing the passage of light along a light path to a filmstrip 20 a orimager 30 for image capture and disallowing that passage at other times.“Shutter” is thus inclusive of, but not limited to, mechanical andelectromechanical shutters of all types. “Shutter” is not inclusive offilm transports and like mechanisms that simply move film or an imager30 in and out of the light path. “Shutter” is inclusive of computersoftware and hardware features of electronic array imagers that allow animaging operation to be started and stopped under control of the cameracontroller 36.

In currently preferred embodiments, the film shutter 102 is mechanicalor electromechanical and the imager shutter 104 is mechanical orelectronic. The imager shutter 104 is illustrated by dashed lines toindicate both the position of a mechanical imager shutter and thefunction of an electronic shutter. When using a CCD, electronicshuttering of the imager 30 can be provided by shifting the accumulatedcharge under a light shielded register provided at a non-photosensitiveregion. This may be a full frame as in a frame transfer device CCD or ahorizontal line in an interline transfer device CCD. Suitable devicesand procedures are well known to those of skill in the art. When using aCID, the charge on each pixel is injected into a substrate at thebeginning of the exposure. At the end of the exposure, the charge ineach pixel is read. The difficulty encountered here is that the firstpixel read has less exposure time than the last pixel read. The amountof difference is the time required to read the entire array. This may ormay not be significant depending upon the total exposure time and themaximum time needed to read the entire array.

CMOS imagers are commonly shuttered by a method called a rollingshutter. CMOS imagers using this method are not preferred, since thisshutters each individual line to a common shutter time, but the exposuretime for each line begins sequentially. This means that even with ashort exposure time, moving objects will be distorted. Given horizontalmotion, vertical features will image diagonally due to the temporaldifferences in the line-by-line exposure. Another method for shutteringCMOS imagers is described in U.S. Pat. No. 5,986,297. In this method,called single frame capture mode, all pixels are allowed to integratecharge during the exposure time. At the end of the exposure time, allpixels are simultaneously transferred to the floating diffusion of thedevice. At this point sequential read out by lines is possible.

An image display 32 is mounted on the outside of the body 24 and,preferably, faces the rear of the camera 10. The image display 32 isdriven by an image display driver 108 and can be turned on to display averification image to preview what a print or other final image isexpected to look like. Signal lines 110 electronically connect theimager 30 through the control system 34 to the image display 32. Theimage display 32 produces a light image (also referred to here as a“display image”) that is viewed by the user.

The control system 34, as earlier discussed, includes the controller 36and memory 112 and also includes an analog-digital converter 114 (alsoreferred to herein as a “A/D converter 114”) (this term is inclusive ofcomponents that also include an analog signal processor and amplifier)and the image processor 38. Other components can also be provided, asdiscussed below, in detail. Suitable components for the control system34 are known to those of skill in the art. Modifications of the controlsystem 34 are practical, such as those described elsewhere herein. Thecontroller 36 can be provided as a single component, such as amicrocomputer or microprocessor, or as multiple components of equivalentfunction in distributed locations. The same considerations apply to theprocessor and other components. Likewise, components illustrated asseparate units herein may be conveniently combined or shared in someembodiments.

The captured analog electronic image is amplified and converted by theA/D converter 114 to a digital electronic image, which is then processedin the image processor 38 and stored in the memory 112.

“Memory 112” refers to one or more suitably sized logical units ofphysical memory provided in semiconductor memory or magnetic memory, orthe like. For example, the memory can be an internal memory, such as aFlash EPROM memory, or alternately a removable memory, such as aCompactFlash card, or a combination of both. “Memory 112”, as usedherein, is separate from the “film unit 18”. Thus, in some embodiments,the camera has both memory 112 and a digital film unit 18.

It is currently preferred that the signal lines 110 act as a data busconnecting the imager 30, controller 36, processor 38, the image display32, and other electronic components.

The controller 36 and image processor 38 can be controlled by softwarestored in the same physical memory 112 that is used for image storage,but it is preferred that the processor 38 and controller 36 arecontrolled by firmware stored in dedicated memory (not separatelyillustrated), for example, in a ROM or EPROM firmware memory. Separatededicated units of memory can also be provided to support otherfunctions.

The respective electronic images correspond to the latent images on theexposed film frames 28, and, after processing, are individually storedin memory 112, each time the filmstrip 20 a is advanced forward oneframe increment following a film exposure. The memory 112 has asuccessive-image storage capacity for a limited number of electronicimages. For convenience, the electronic images stored in a single camera10 are generally treated herein as all being of the same size or aboutthe same size. This is the case in currently preferred embodiments; butis not limiting.

The embodiment shown in the figures has space for storing up to 50captured electronic images. This number is exceeds the maximum number oflatent images on currently available APS film units, which is 40. When alatent image is exposed, the filmstrip 20 a is advanced a frameincrement. This is detected by one or more sensors 116 which signal thecontroller. In response, the controller 36 decrements a frame count (thenumber of film frames 28 available on the filmstrip 20 a that remain tobe exposed) stored in memory 112 by one. The frame count can go forwardfrom zero or backward from 15, 25, or 40 depending on whether thefilmstrip 20 a has a 15-exposure, 25-exposure, or 40-exposure length.The current frame count is shown in an information display 118. In thecamera shown in FIGS. 3-4, a pair of identical film perforation sensors116 for sensing successive pairs of film perforations 120 in thefilmstrip 20 a are mounted in respective pockets in the film pressureplaten 72 and are connected to the controller.

The manner in which electronic images are stored in memory 112 is notcritical. For convenience, the storing of electronic images is discussedherein in terms of allocated separate single-image addresses or blocks“1” to “50” in the memory 112. Consistent with the frame count,respective frame numbers for the captured electronic images are storedat the single-image addresses “1” to “50” in the memory 112. Therespective electronic images stored in the memory 112 at thesingle-image addresses can be accessed separately and shown individuallyon the image display 32.

The camera 10 has a communications port 124, through which theelectronic images stored in memory 112 can be downloaded under thecontrol of the controller 36 to a imaging device 126 (illustrated as acomputer, and only in FIG. 1) such as a computer or network or digitalappliance, using a communications protocol, such as the USB protocol.The camera 10 can optionally provide for downloading of individualelectronic images; however, is currently preferred that all images inmemory 112 be downloaded at each download event. The reason thisapproach is preferred, is that, in preferred embodiments, the size ofthe electronic images is relatively small and download times arerelatively quick; and, with this in mind, it is better for the user todownload all images, then discard any that are not desired, rather thanpresent the risk that wanted images will not be downloaded or increasethe time necessary to download images by increasing the number stepsrequired.

The controller 36 facilitates the transfers of the image, along thesignal lines 110, between the electronic components and provides othercontrol functions, as necessary. The controller 36 includes a timinggeneration circuit (not separately illustrated) that produces controlsignals for all electronic components in timing relationship.

Calibration values for the individual camera 10 are stored in acalibration memory (not separately illustrated), such as an EEPROM, andsupplied to the controller 36. The controller 36 operates the memory 112or memories and the drivers including the zoom drivers 94, focus driver130, imager driver 74, image display driver 108, aperture drivers 132,and film and imager shutter drivers 134,136. The controller 36 connectsto a flash circuit 137 of the flash unit that mediates flash functions.

It will be understood that the circuits shown and described can bemodified in a variety of ways well known to those of skill in the art.It will also be understood that the various features described here interms of physical circuits can be alternatively provided as firmware orsoftware functions or a combination of the two. The controller 36 isillustrated as a single component, but it will be understood that thisis a matter of convenience in illustration. The controller 36 can beprovided as multiple components of equivalent function in distributedlocations. The same considerations apply to the processor 38 and othercomponents. Likewise, components illustrated as separate units hereinmay be conveniently combined or shared in some embodiments.

The digital electronic image stored in memory 112, is accessed by theprocessor 38 and is modified so as to provide a required derived image.As a part of showing a derived image on the image display 32, the camera10 may modify the derived image for calibration to the characteristicsof the particular display. For example, a transform can be provided thatmodifies each image to accommodate the different capabilities in termsof gray scale, color gamut, and white point of the display and theimager and other components of the electronic capture unit. It ispreferred that the display is selected so as to permit all of theverification image to be shown; however, more limited displays can beused. In the latter case, the displaying of the verification imageincludes calibration that cuts out part of the image, or contrastlevels, or some other part of the information in the verification image.

The derived images can also be modified in the same manner that imagesare enhanced in fully digital cameras. For example, processing canprovide interpolation and edge enhancement. A limitation here is thatthe derived images are intended to correspond to photofinished archivalimages and, thus, enhancements should limited so as to not render thederived image dissimilar to the corresponding photofinished archivalimage. If the archival image is an electronic image, then comparableenhancements can be provided for both verification and archival images.Digital processing of an electronic archival image can also includemodifications related to file transfer, such as, JPEG compression, andfile formatting.

Enhancements can be provided to match the calibrated derived image tooutput characteristics of a selected photofinishing channel.Photofinishing related adjustments assume foreknowledge of thephotofinishing procedures that will be followed for a particular unit ofcapture media. This foreknowledge can be made available by limitingphotofinishing options for a particular capture media unit or bystandardizing all available photofinishing or by requiring the user toselect a photofinishing choice, for example by entering a character on acontrol pad or setting a switch. This designation can then direct theusage of particular photofinishing options and can provide for a director indirect indication of the effect in a derived image. The applicationof a designation on a capture media unit could be provided by a numberof means known to those in the art, such as application of a magnetic oroptical code.

Derived images can be prepared from the electronic image before beingneeded or as needed, as desired, subject to the limitations ofprocessing speed and available memory. To minimize the size of thememory 112, an electronic image can be processed and stored as a lowerresolution image, before a succeeding image is read out from the imager30.

Different types of image display 32 can be used. For example, the imagedisplay 32 can be a liquid crystal display (“LCD”), a cathode ray tubedisplay, or an organic electroluminescent display (“OELD”; also referredto as an organic light emitting display, “OLED”).

The image display 32 is preferably mounted on the back or top of thebody 24, so as to be readily viewable by the photographer immediatelyfollowing a picture taking. One or more information displays 118 can beprovided on the body 24, to present camera information to thephotographer, such as exposures remaining, battery state, printingformat (such as C, H, or P), flash state, number of prints ordered, andthe like. For convenience, the information display 118 is generallydiscussed here in the singular. The information display 118 and imagedisplay 32 can be provided by separate display devices or both beprovided by contiguous parts of a common display device. The informationdisplay 118 can be deleted if information is instead provided on theimage display 32 as a superimposition on the image or alternatelyinstead of the image (not illustrated). If separate, the informationdisplay 118 is operated by an information display driver 138.

In the embodiment shown in FIGS. 3-4, the image display 32 is mounted tothe back of the body 24 and the information display 118 is mounted tothe body 24 adjacent to the image display 32 such that the two displays32,118 form part of a single user interface 140 that can be viewed bythe photographer in a single glance. The image display 32 and aninformation display 118 can be mounted instead or additionally so as tobe viewable through the viewfinder 78 as a virtual display (not shown).

It is preferred that the image display 32 is operated on demand byactuation of a switch (not separately illustrated). The image display 32is turned off by again actuating the switch or by initial depression ofthe shutter release 26. The image display 32 can also be automaticallyturned off by a timer for battery conservation. The timer can beprovided as a function of the controller 36. When the image display 32is actuated, earlier captured images can be reviewed using a usercontrol 144 to sequence through the images.

Referring now particularly to FIGS. 3-4, the user interface 140 of thecamera 10 includes the shutter release 26, the “zoom in/out” toggle 142that controls the zooming of the lens units, and other user controls 144along with the image display 32 and the information display 118. Theshutter release 26 operates both shutters 102,104. To take a picture,the shutter release 26 is actuated by the user and trips from a setstate to an intermediate state, and then to a released state. Theshutter release 26 is typically actuated by pushing, and, forconvenience the shutter release 26 is generally described herein inrelation to a shutter button that is initially depressed through a“first stroke”, to actuate a first switch S1 and alter the shutterrelease 26 from the set state to the intermediate state and is furtherdepressed through a “second stroke”, to actuate a second switch S2 andalter the shutter release 26 from the intermediate state to the releasedstate. Like other two stroke shutter releases well known in the art, thefirst stroke actuates exposure-delimiting camera components, such asautofocus, autoexposure, and flash unit readying; and the second strokeactuates capture of the archival image.

Referring now to FIG. 2, when the shutter release 26 is pressed to thefirst stroke, the taking lens unit 50 and combined lens unit 84 are eachautofocused to a detected subject distance based on subject distancedata sent by the rangefinder 96 to the controller 36. The controller 36also receives data indicating what focal length the lens units 50,84 areset at from one or both of the zoom drivers or a zoom sensor (notshown). The camera 10 also detects the film speed of the film cartridge18 a loaded into the camera 10 using the reader 67 and relays thisinformation to the controller 36. The camera 10 obtains scene brightness(Bv) from components, discussed below, that function as a light meter.The scene brightness and other exposure parameters are provided to analgorithm in the controller 36, which determines a focused distance,shutter speeds, apertures, and optionally a gain setting foramplification of the analog signal provided by the imager 30.Appropriate signals for these values are sent to the drivers via a motordriver interface (not shown) of the controller 36. The gain setting issent to the A/D converter 114.

The camera 10 assesses ambient lighting using the imager 30 or aseparate detector 146 (indicated by dashed lines in FIG. 2) or both. Thedetector 146 has an ambient detector driver 148 that operates a singlesensor or multiple sensors (not shown). In some embodiments, theevaluation image capture unit 16 is used to assess ambient lighting. Inthose embodiments, one or more electronic images are captured prior tocapture of the archival image. The captured electronic image data fromone or more of these preliminary images is sampled and scene parameters,such as automatic setting of shutter speeds and diaphragm settings, aredetermined from that data. These preliminary electronic images can becaptured in a continuing sequence as long as the capture system 12 is ina preliminary mode. For example, preliminary images can be captured,seratim, as long as the shutter release 26 is actuated through the firststroke and is maintained in that position. This capture of preliminaryimages ends when the shutter release 26 is returned to a stand-byposition or is actuated through the second stroke for archival imagecapture. The preliminary electronic images could be saved to memory 112;but, except as otherwise described here, are ordinarily discarded, oneafter another, when the replacement electronic image is captured toreduce memory 112 usage. The preliminary images can also be provided tothe image display 32 for use by the photographer, prior to picturetaking, in composing the picture. This use of the image display 32 as anelectronic viewfinder 78 greatly increases energy usage and is notpreferred for that reason.

The electronic capture unit is calibrated during assembly, to providemeasures of illumination, using known values. For example, thecontroller 36 can process the data presented in a preliminary imageusing the same kinds of light metering algorithms as are used formultiple spot light meters. The procedure is repeated for eachsucceeding preliminary image. Individual pixels or groups of pixels takethe place of the individual sensors used in the multiple spot lightmeters. For example, the controller 36 can determine a peak illuminationintensity for the image by comparing pixel to pixel until a maximum isfound. Similarly, the controller 36 can determine an overall intensitythat is an arithmetic average of all of the pixels of the image. Many ofthe metering algorithms provide an average or integrated value over onlya selected area of the imager 30 array, such as an upper middle region.Another approach is to evaluate multiple areas and weigh the areasdifferently to provide an overall value. For example, in a centerweighted system, center pixels are weighted more than peripheral pixels.The camera 10 can provide manual switching between different approaches,such as center weighted and spot metering. The camera 10 canalternatively, automatically choose a metering approach based on anevaluation of scene content. For example, an image having a broadhorizontal bright area at the top can be interpreted as sky and given aparticular weight relative to the remainder of the image.

Under moderate lighting conditions the imager 30 can provide lightmetering and color balance determination from a single preliminaryimage. More extreme lighting conditions can be accommodated by use ofmore than one member of the series of preliminary electronic imageswhile varying exposure parameters until an acceptable electronic imagehas been captured. The manner in which the parameters are varied is notcritical.

After the controller 36 receives the scene brightness value, thecontroller 36 compares scene brightness to a flash trip point. If thelight level is lower than the flash trip point, then the controller 36enables full illumination by the flash unit 48, unless the user manuallyturned the flash off. Appropriate algorithms and features for theseapproaches are well known to those of skill in the art.

A second switch S2 actuates when the shutter release 26 is furtherpushed to a second stroke. When the second switch S2 actuates, the filmshutter 102 is tripped and the capture of the latent image exposure onthe film frame 28 begins. The film shutter 102 momentarily opens for aduration referred to herein as a “archival image exposure timeinterval”. The imager shutter 104 is also actuated and momentarily opensduring the archival image exposure time interval to capture the initialelectronic image.

When a film unit 18 is to be removed from the camera 10, the film door46 is opened and the film unit 18 is extracted. The camera 10 has a filmunit detector or signaler 150, which signals the controller 36 when afilm unit 18 is present and the film door 46 has been closed. Inresponse, the controller 36 can cause the information display 118 toshow and icon or other indicia (not illustrated) that indicates whetheror not a film unit 18 is loaded and the film door is shut.

The image display 32 can be used to verify the quality of a justcaptured image and can also be used to review earlier captured images.User controls 144 are provided for these functions. In the camera 10shown in the figures, a verification image of the last captured archivalimage is accessed by pressing a verify button 152. This activates theimage display 32 and disables image capture while the image display 32is actuated. The user can change from a the last captured image toearlier captured images by sequencing through the images using therespective user control (not separately illustrated) In a particularembodiment, the zoom toggle 142 is used for this function when the imagedisplay is activated. Some features of final images produced from thearchival images can be modified while the verification images areviewed, as discussed below in detail.

In the embodiments in the figures, it is highly preferred that thecamera memory 112 has sufficient capacity to store an electronic imagecorresponding to each of the film frames 28 of the film unit 18, sincethis allows the user to review all of the images of a film unit 18 atone time. Since the film units 18 come in different capacities, thememory 112 needs sufficient capacity to store an electronic imagecorresponding to each of the film frames 28 of a film unit 18 having thelargest capacity. This provides excess capacity in memory 112 whensmaller capacity film units 18 are used. It is preferred that the memory112 of the camera 10 has sufficient capacity to provide some excess overeven the largest capacity film unit 18.

The excess memory capacity can be used to allow the user to reviewelectronic images corresponding to archival images of earlier used filmunits 18. The captured electronic images corresponding to the latentimages in the film units 18 are not erased from memory 112 when therespective film unit 18 is removed from the camera 10; instead, once thememory 112 is fill, the oldest captured electronic image is overwrittenby the newest captured electronic image. (If necessary, two oldelectronic images may be deleted if required to free enough memory 112to store one new image). The order in which the images are replaced,first in-first-out, corresponds to many practices in inventory controland the like and is also referred to herein by the term “FIFO”.

Since the memory 112 is large enough to hold more than electronic imagesfrom more than one roll of film, the memory 112 therefore holds twotypes of electronic images: current electronic images corresponding tothe latent images on the exposed frames 28 of the film unit 18 currentlyloaded in the camera 10, and past electronic images corresponding to thelatent images on the exposed frames 28 of one or more film units 18earlier exposed in the camera 10. By storing both current images andpast images, the user can always view or download a last series ofelectronic images, within the limits of storage capacity, even if theyremoved a first film unit and started a second film unit.

Selective Image Exclusion from First In-First Out Electronic ImageOverwriting

Referring now particularly to FIGS. 1, 5, and 7-9, electronic images areavailable for downloading from the memory 112 of the camera 10, only ifthe electronic images have not yet been overwritten. This presents aproblem if the user wants to download a few images, but uses severalfilm units before downloading the electronic images. The automatic FIFOimage replacement routine, above-described, will replace some or all ofsuch electronic images before the images can be downloaded. This effectof the FIFO deletion cycle can be overcome by increasing the size of thememory 112 in the camera 10, but this approach adds cost and only delaysthe onset of the same problem.

A better solution is for the user to selectively assign save tags (alsoreferred to herein simply as “tags”) to selected images in the memory112 of the camera 10. The resulting tagged images are withdrawn fromautomatic FIFO replacement. Untagged images remain subject to FIFOreplacement.

Referring now to FIG. 5, a first plurality of electronic images arecaptured (154). This group of images is sufficient to fill than thememory 112 of the camera 10 to capacity. A second plurality ofelectronic images are then captured (156). Following capture of thefirst image (indicated by an indent to the right) and at any time afterthat during the course of the capture (154,156) of the electronic imagesof the first or second plurality, the user can assign (158) tags toselected images.

After electronic images in memory 112 are tagged, those images areretained (160) until terminated during the FIFO replacement (162) ofuntagged images. The tags stay until terminated automatically when therespective electronic image is downloaded (164) from the camera 10. Theuser also has the option of selectively terminating (not illustrated inFIG. 5) individual tags, at any time after tagging. In a particularembodiment, tagged images are also terminated (not illustrated) byexpiration of a time period, such as one year from the date of captureor six months from the date of tagging.

In any case, the termination of tags is unrelated to FIFO imagereplacement and independent of capture of new images. Once the tag isremoved the resulting untagged electronic image is not immediatelyerased from the memory 112, but rather enters the FIFO queue of untaggedimages in date and time order. Each untagged image is eventuallyoverwritten when it becomes the oldest untagged image and space isneeded for a new electronic image.

As FIG. 5 illustrates, the capturing of electronic images (154,156),tagging (158), and terminating (164) of tags can all occur during thesame general time period. As a result the number of electronic images inthe first plurality, that is, the number of electronic images that canbe captured before memory 112 is filled to capacity can go up and down,as electronic images are tagged and untagged. It is desirable to retainmemory space for an electronic image corresponding to each frame of acurrently loaded film unit 18. This can be accomplished by limiting thenumber of electronic images that can be tagged as saved images, to afixed number, so that there is always enough memory 112 remaining tostore in memory 112 all electronic images corresponding to exposedframes 28 on the current film unit 18 without overwriting any taggedimages. For example, tagged images may be limited to 10, so that allimages on a 40 exposure film unit can be saved in a memory 112 with 50blocks. In this case, the maximum number of untagged electronic imagesstored in memory 112, is 50 less the number of tagged images at anygiven time, which is between 0 and 10. Thus, the maximum number ofsaved, untagged images remains between 40 and 50. If a 25 exposure filmunit is used, then the number of tagged images available is still 10 andthe number of untagged images is still between 40 and 50; however, thereis memory space for all of the images in the current film unit alongwith some images from a preceding film unit.

The tags are assigned or unassigned by actuating a tag selector 166while the respective electronic image is displayed on the image display32. The tag selector 166 can be a dedicated or shared control button 144or the like that is pressed to tag or untag the displayed electronicimage. FIGS. 7-9 illustrate a user control 144 provided by designationof a button 144 a using the information display 118. In FIG. 7 averification image derived from a respective electronic image is shownon the image display. The particular electronic image is untagged andtags are available for use. The controller causes the informationdisplay to designate a particular user control 144 that can be actuatedto tag the image. In FIG. 8 the verification image is that of a taggedelectronic image. The information display is configured by thecontroller to provide a user control 144 b for untagging the image. InFIG. 9, the electronic image is untagged, but the maximum number oftagged images are already in use. The controller has configured theinformation display to show the Tag image indicia grayed out and theassociated button 144 a is disabled. Tagged images are identified byindicia 168 superimposed on the image display 32 or presented on theinformation display 118 or both. For example, the indicia can be atextual message of “tag” or “locked” or the like or an icon of the sameeffect.

The review of earlier images provided by the camera 10 can be variableto allow review of all images in chronological or other order and,alternatively, review of tagged or untagged images only in chronologicalor other order. The zoom toggle can be used to move between images. Forelectronic images not associated with film loaded in the camera 10,there can be provided an indicia (not shown) on the image displayshowing that the respective image is not from the current roll and APSphotofinishing related features, such as print quantity, are no longersubject to change.

The tag selector 166 is connected to a memory manager, which can be aseparate component, but is most conveniently provided by software andhardware features of the controller 36. The memory manager controls theFIFO queue and excludes tagged images from the queue. The memory manageris operatively connected to the communications port 124 and signals thememory 112 writer to terminate tags when respective image files aredownloaded through the communications port 124. The memory manager also,optionally, includes the clocks 170 that are used to determine when timeperiods expire for the different electronic images in memory 112.

Referring to FIG. 12, a “tag 172” is a feature of an electronic imagefile 174 that, in combination with appropriate control system 34software and hardware, prevents the memory 112 from erasing/writing overthe respective image file recorded in the memory 112. Stated anotherway, a tag 172 is a type of image metadata that is associated with anindividual image file and provides the indicated function. The fileshown also has a header 176 and the data 178 for the particular image.

Some film units 18, such as APS film give the photographer an option ofsetting the number of prints for each image. When such a film unit 18 isremoved from the camera 10, any electronic image with the print quantityset to zero that does not have a save tag stored in the associatedelectronic image, can be moved to the head of the FIFO image replacementqueue. This can be done by changing the date associated with therespective files and is the equivalent of automatically erasing thefiles from memory 112. This operation delays overwriting of images thathave a non-zero print quantity.

The camera 10 can optionally allow capture of scenes as electronicimages without an accompanying film image. Such electronic-only imagescan be automatically tagged at the time of capture. Once captured, suchelectronic-only images are then treated in the same manner as othertagged images.

Use of a Dynamic Number of Stored Electronic Images Protected fromOverwriting

Referring now particularly to FIGS. 1 and 6-12, rather than being fixed,the number of tagged images available can be dynamically varied to allowthe maximum number of tagged images possible with the film unit 18currently loaded and the capacity of the memory 112. For example, thememory 112 can have a capacity of 50 electronic images and film units 18usable with the camera can have a maximum number of exposures of 15, 25or 40. If the 15 exposure film unit is used, then 35 electronic imagescan be tagged. If the 25 exposure film unit is used, then 25 electronicimages can be tagged. If the 40 exposure film unit is used, then 10electronic images can be tagged. Of course, a lesser number of taggedimages than the difference between the memory capacity and the number offilm frames can also be provided, if desired.

In order to operate in this manner, the camera 10 determines the numberof exposures available when a film unit 18 is loaded. This informationis currently available on some film units 18 in the form of a bar codeor the like. With APS film units, a data disk (not shown) on the end ofthe canister 22 b indicates the number of exposures on the film unit 18in the form of a circular bar code. The camera 10 has a reader 67 thatcan read the indication of the number of exposures on the film unit 18and convey that information to the controller 36. With an APS film unit18, the reader 67 can be a bar code reader in the form of an infraredemitter-sensor pair.

Some APS cameras 10 allow mid-roll change (abbreviated “MRC”, sometimesreferred to as mid-roll interchange “MRI”). Those cameras 10 detect thenumber of exposures available on a loaded film unit 18 and, in addition,detect the number of film frames 28 that have already been exposed. Thenumber of tagged electronic images available, in a camera 10 thatprovides MRC can be based on the number of the unexposed film frames 28available rather than the total number of film frames 28 on a film unit18. Alternatively, the number of tagged electronic images available canbe determined in the same manner as when a fully unexposed film unit 18is loaded. The latter approach is currently preferred, since it has alesser likelihood of confusing the user. For convenience, the discussionhere is generally limited to situations in which a film unit 18 isremoved only after exposure of all available film frames 28.

In order for the camera 10 to determine the maximum number of taggedimages possible with the film unit 18 currently loaded, the camera 10also has to know the capacity of the camera memory 112. The maximumnumber of tagged images possible is equal to the difference between thecapacity of the memory 112 and the number of film frames 28 available onthe film unit 18 currently loaded.

The capacity of the memory can be defined artificially as a fraction ofthe total memory of the camera. This approach may be needed for memory112 that is shared with other components.

The capacity of the memory 112 is divisible, for purposes of analysisinto unit spaces or subdivisions of the memory that can each hold asingle electronic image captured by the camera. This analysis providesan integer value, in electronic image spaces, of the capacity. If allelectronic images captured by the camera are of the same size, eitherinitially or after a standardized compression procedure, then becapacity of the memory is simply a matter of dividing the physicalcapacity of the memory by the unit size of the electronic images. Thiscalculation can be done ahead or provided as needed by the controller.

If electronic images stored by the camera are not necessarily of thesame size, either due to differences in the effect of compression or forother reasons, then in the camera can still make the same calculation;but the calculation must be based upon a nominal size electronic image.To save processing, it is preferred that this nominal size electronicimage be predefined rather than being estimated on the basis of earliercaptured images. Any portion of memory attributable to the remainder ofthe analytical division used to determine the integer capacity, canprovide a small reserve to accommodate one or more stored images ofslightly excessive size. If wide variation in stored image sizes orother increase memory demand is expected, then the reserve can beincreased in size by decreasing the capacity by one or more units.

The capacity of the memory can be set to an integer number of electronicimage units that represent an arbitrary fraction of the total memory ofthe camera. This can be done by the controller and is useful, forexample, if the physical memory 112 is removable and replaceable byanother memory component of different capacity. (The memory 112 and thedigital film unit 18 can share the same component; but are distinguishedon the basis of the nature of the images stored and the use to whichthose images are put. The use of a removable component for memory 112adds unnecessary complexity and for that reason is not preferred.)

In an embodiment in which the number of tagged images is set to a lowernumber than would be possible using all the capacity of the memory, thenumber of tagged images is still dynamic. The total of the number oftags plus the number of available film frames is kept constant. Thetotal represents a maximum number of tags can be made available in thatcamera, by using a film unit with a minimum number of film frames. Forexample, a camera with a maximum capacity of 60 electronic images of anominal size can be limited to a total number of tags plus film framesof 50. If available film units have 15, 25, and 40 film frames, then themaximum number of tags is 35. If a film unit is loaded that has 15exposures, this provides for the maximum number, 35 tags. If a film unitis loaded that has 25 exposures, then the number of tags is 25.

Referring now to the method shown in FIG. 6, a first film unit 18 isloaded (180) into the camera 10. The first film unit 18 has a firstquantity of film frames 28 available for exposure. This first quantityis determined (182) by the reader 67 and is communicated to thecontroller. A tag number is then set (184) by the controller asabove-discussed.

The tag number is a preset fraction of the first quantity. In theembodiments discussed above; the tag number is 35, if a 15 exposure filmunit 18 is used; 25 if a 25 exposure film unit 18 is used; and 10 if a40 exposure film unit 18 is used.

A plurality of electronic images are then captured (186) and stored(188) in the memory 112 of the camera 10. Individual tags areselectively assigned (190) by the user to one or more of the electronicimages resulting in respective tagged images. The first film unit 18 isremoved (192) and a second film unit 18 is loaded (194). The second filmunit 18 has a second quantity of film frames 28 available for exposure.This second quantity is determined (196) by the reader 67 and iscommunicated to the controller 36.

The controller 36 then resets (198) the tag number, on the same basis aswith the first film unit 18. The number of images protected fromoverwriting, thus, is dynamic and a function of the currently loadedfilm unit 18.

The controller 36 totals the number of tagged images. This total iscompared to the tag number after resetting. A warning is displayed (200)when the tag number is less than the number of tagged images.

It is convenient, if the controller 36 maintains a running total oftagged images during use, determining the number of tagged images priorto storing each new electronic image. On the other hand, if desired, thecontroller 36 can total the number of tagged images only prior tostoring new images following the filling of the memory 112 to capacity.This approach is slightly more complex, but reduces processingrequirements during initial image captures.

The warning can be presented in any manner, such as by indicia or anaudible message using a speaker (not shown) on the camera 10, or acombination of the two. It is preferred that the warning is easilyunderstood by the user. For this reason, a warning in the form of asimple warning light or the like, is not desirable. A warning in theform of a textual message or easily understood icon is currentlypreferred. Warning indicia can be presented on the image display 32 orthe information display 118 or both. FIG. 10 illustrates an examplewarning message which indicates that the next 25 exposures willoverwrite tagged images. The message also suggests downloading and givesthe user the option of pressing one button to bring up verificationimages for review and untagging, as necessary. The message also allowsthe user to proceed by assenting to the overwriting of a tagged image(by pressing the “Yes” button). The message is repeated, with the number25 diminishing as tagged images are overwritten, as additional newimages are captured.

It is the intent of the warning to convey to the user that earliertagged electronic images will be untagged and eventually overwritten andreplaced with newly captured electronic images on a FIFO basis. It ispreferred that the warning message indicate the number of tagged imagesthat will be overwritten during the course of picture taking using thenew film unit 18, since this gives the user a better idea as to theproblem faced.

The user can respond to the warning message in several different ways.The user can unload the second film unit 18 and load a replacement filmunit 18 having a lesser number of exposures than the second film unit 18and, preferably, the same number of exposures as the first film unit 18.Another alternative available to the user when the warning is presented,is to immediately download electronic images before capturing additionalfilm images. Still another alternative, is for the user to review theelectronic images stored in the camera 10 and change tags such that canbe total number of tagged images matches the current tag number. To makethis more convenient, the earlier discussed warning can be interactive.In this case, after the user presses the edit images button 144 c inFIG. 10, an image is displayed in edit mode, as shown in FIGS. 7-9.After cycling through images, as desired, the user can press button 144b, shown in FIG. 8, to untag one of the images. The display next shows awarning message like that shown in FIG. 10, except that the exposurecount is reduced by one. The warning message is repeated each time a tagis removed, counting down the number of tagged images to be overwrittenuntil space is available for all of the images of the new film unit orthe user decides to proceed (by pressing the button “Yes” in FIG. 10)without removal of any more tags. Alternatively, the warning message,altered to show the correct count of tagged images subject tooverwriting, is repeated only when the user exits the editing mode bypressing the shutter release 26 part way down or pressing another button144 that provides that function, such as an “Enter” button (notseparately identified in the drawings.

One more alternative for the user, is to respond to the warning byassenting to termination of the tag on the oldest tagged image. The userresponse can be actuation of a specific button, as illustrated in FIG.10; or, alternatively, one or more actions leading to capture of a newimage. The action or actions indicating user assent are signaled to thememory 112 module; which, in response, untags the oldest tagged image.The newly captured image is then saved. This process can be repeatedwith additional captured images until the total number of tagged imagesmatches the current tag number.

The change in tag number has the effect of adding the excess taggedimages to the end of the FIFO replacement queue, in capture date order.This can be considered a second FIFO replacement queue of excess taggedimages that succeeds the first FIFO replacement queue of untaggedimages.

Downloading of Electronic Images Having Metadata Identifying ImagesPreviously Excluded from First In-First Out Overwriting

Referring now to FIGS. 1 and 11-12, in a particular embodiment of thecamera 10 and method, the electronic images are downloaded through thecommunications port 124 to provide downloaded images in an imagemanipulation device 126, such as a personal computer, networked device,or digital appliance. The image manipulation device includes a computermonitor 202 that allows the downloaded images to be visualized and alsoincludes software and hardware necessary to manipulate the downloadedimages in some manner, such as digital editing, or printing, orphotofinishing or the like.

In this embodiment, all of the electronic images in the camera 10 aredownloaded, including both tagged images and on tagged images; when animage download is undertaken. The downloaded images 174 retain the tags172, which were used in the camera 10 to identify the tagged images forexclusion from overwriting during FIFO electronic image replacement.These tags 172 can be identified by the image manipulation device and,using appropriate software known to those of skill in the art, can bedisplayed to the user along with the respective electronic image in thesame manner as other metadata associated with an electronic image.

The system, as shown in FIG. 1, includes the camera 10 and an imagemanipulation device 126, such as a personal computer, connected orconnectable through the communications port 124. The camera 10 differsfrom those earlier described in that the controller 36 transmitselectronic images for downloading that include the tags 172 as metadatain the respective image files 174. A downloaded image is illustratedschematically in FIG. 12 and includes a file header 176, image data 178,and the tag 172.

The manner in which the downloaded images and the tags are displayed bythe image manipulation device is not critical. The downloaded images canbe displayed individually or in groups. Tags can be indicated byindicia, such as explanatory text or and icon. For example, in FIG. 11,four downloaded images 204 are shown and tags of respective images areshown by the superimposed word “tag” 206. Icons or other indicia couldalso be used.

The tag, whatever its form, simply identifies on the image manipulationdevice, which particular images were saved from overwriting in thecamera 10. This information is useful to the user, because it tells theuser which of the images were saved from overwriting in the camera 10.The information that a downloaded image was save tagged in the camera 10is a quick and easy indication that the image was considered to beimportant at some point in time. This suggests to the user that theparticular downloaded image may be more important than the untaggedimages and that the user may want to give more careful consideration tothat downloaded image. The user can then make use of this information inorganizing or printing or otherwise dealing with the downloaded images.This is particularly useful if the images were captured by more than onephotographer. Whoever downloads the images knows that tagged images werevalued by another photographer and can preserve those images orotherwise act on that information.

The advantage of this approach is that it is an extremely simple yes-nodecision, and makes secondary use of a user decision already requiredduring picture taking as a result of space constraints. This approach isnot an organizational scheme, since there are only two categories, savefrom overwriting and do not save, and those categories do notdifferentiate image content. Much picture taking occurs during hectic orconfusing circumstances. The simple decision to save or not save is mucheasier make in such circumstances than are organizing or categorizingdecisions.

Camera Having Electronic Images Corresponding to Current Film ImagesAutomatically Excluded from First In-First Out Overwriting and Method

Referring now to FIGS. 13-17, in a modification of the cameras andmethods, one subset of electronic images stored in camera memory isautomatically excluded from first in-first out overwriting. Images ofthe other subset of electronic images are replaced on a FIFO basis whenmemory capacity is exceeded. The characteristic that defines the subsetsis the presence or absence of a corresponding film image. The electroniconly images can be retained and the electronic images corresponding tofilm images replaced as space is needed; however, it is currentlypreferred that the electronic images stored in memory, which correspondto latent images on a currently loaded film unit, are automaticallyexcluded from first in-first out overwriting. The other subset ofelectronic images, which do not have corresponding film images in a filmunit loaded in the camera, are replaced on a FIFO basis when memorycapacity is exceeded. When the film unit is removed, the correspondingelectronic images are moved to the first in-first-out replacement queue,in date and time order of capture.

The term “capacity” is used in the same sense here as elsewhere in theapplication. The capacity of the memory in a particular camera issubject to the same considerations as above discussed. It is preferredthat the capacity of the memory is sufficient to hold an electronicimage corresponding to each latent image on an expected film unit. ForAPS film, expected film units have 15, 25, or 40 film frames and thepreferred memory capacity is sufficient to hold more than 40 electronicimages. An excess of capacity beyond that needed to hold electronicimages corresponding to the highest expected number of film images iseven more preferred, since this allows the storage of electronic imagesfor an entire film unit plus some number of electronic only images.

FIG. 17 illustrates the modified camera, which is like the cameraearlier described but simplified by removal of unnecessary features. Forexample, the tag selector is deleted. The camera can combine thefeatures earlier disclosed with those of this modification; however, theuse of both tags and automatic exclusion in the same camera is currentlyexpected to be confusing to the user and is therefore not preferred.

In FIG. 17, the camera 10 has a film unit detector or signaler 150,which signals the controller 36 when a film unit 18 is present in thefilm holder and the film door 46 has been closed. The controller treatsthe signal as an indication that a film unit, earlier held by the filmholder, has been removed and replaced by another film unit. The cameracan alternatively, or additionally, include a reader 67, which canprovide a similar function by reading an initial film unit, reading theabsence of a film unit, then reading the second film unit loaded intothe camera.

The controller categorizes the electronic images in memory of the cameraas retained images, if the respective film unit is present, and asnon-retained images if the respective film unit is absent. The retainedimages are recategorized by the controller as nonretained images whenthe respective film unit is removed. The manner in which the controllerprotects the retained images from FIFO overwriting and allows FIFOoverwriting of the nonretained images is not critical. A wide variety ofwrite protection schemes used in computers and other hardware can beused. For example, retained and non retained images can be kept in thedifferent logical or physical partitions of memory, with different writeprotections and be switched between the partitions as needed. It iscurrently preferred that retained images be protected by the use oftags, in the same manner as earlier described. A distinction from theearlier description, is that the camera here has no tag selector, sincethe user has no ability to directly tag or untag images. The presence orabsence of a “tag” could be directly indicated to the user, similar towhat is shown on the image display 32 in FIG. 8; but this is notpreferred, since the term “tag” is not explanatory in this case. Apreferred approach is illustrated in FIGS. 18-19, in which the userinterface has a message 210, identifying a corresponding film frame of adisplayed electronic image or another message 212 identifying theelectronic image as lacking a corresponding film frame on the film unit(if any) currently loaded in the camera.

The camera includes a communications port operatively connected to thememory and controller. Electronic images are be downloaded through thecommunications port by connecting to a networked or local device, asearlier discussed. The camera can be configured to have the downloadingchange all electronic images to non-retained images; but, forsimplicity, it is preferred that the downloading of the electronicimages does not effect the status of the electronic images in memory asretained or non-retained images.

The camera can be further modified to provide mid-roll change. When anincomplete film unit is removed for mid-roll change, the controller cantag the electronic images corresponding to the latent images in the filmunit, in the same manner as earlier described. The tags are then used,as earlier described, to prevent overwriting of the tagged electronicimages. When said the film unit is reloaded into the camera, the tagscan be removed and the electronic images corresponding to the latentimages in the film unit can be treated in the same manner as if the filmunit had never been removed. This assumes that the user, during anymid-roll change, only switches from a first film unit to a second filmunit and then back to the first film unit. In other situations, it isnecessary for the camera to be able to identify the first film unit whenit is reloaded. The identification of film units in cameras by readingidentification numbers, is well-known to those of skill in the art andany of a variety of approaches can be used. For example, the reader 67,can read an identification number on the film unit. If tags are providedby mid-roll change, then it is preferred that the tags are terminatedafter expiration of a period of time, as earlier discussed, in case thecorresponding film unit is never reloaded.

It is currently preferred that, at mid-roll change, the controller ceaseblocking replacement of the electronic images corresponding to thelatent images on the film unit. The electronic images corresponding tothe latent images on the mid-roll changed film unit, then enter the FIFOreplacement queue, in date and time order of capture. This approach issimpler and less confusing than the use of tags and still allowsmid-roll change. Another likewise preferred alternative is to notimplement mid-roll change in the camera. For convenience, mostdiscussion here is limited to embodiments in which mid-roll change isnot implemented.

The camera can be limited to a mode in which a film image and acorresponding electronic image are captured at every capture event. Itis preferred that the camera is selectively switchable by the user,between two modes: a film and electronic capture mode and an electroniconly capture mode. A two-position mode switch 208 that can provide thisfunction is illustrated in FIG. 17. Electronic only capture mode imagesdo not have a corresponding latent image and immediately enter the FIFOreplacement queue. When a film unit is removed electronic imagescorresponding to latent images in that film unit, at that time, enterthe FIFO replacement queue. Multiple queues and complex queue orders canbe provided, but it is preferred, for simplicity, that all electronicimages in the FIFO replacement queue are in overall time and date orderof capture.

The camera can alternatively provide three modes: a film and electroniccapture mode, an electronic only capture mode, and a film only capturemode in which no electronic image is captured. This approach is notpreferred, because this mode lacks the benefit of reviewing averification image after scene capture.

FIGS. 13-16 illustrate, in diagrammatical form, four different examplesof capture of a sequence of images using the modified camera of FIG. 17.In these examples, the camera memory is defined as having a capacity tohold seven electronic images of uniform size and the film unit isdefined as having film frames for five latent images. It will beapparent that these numbers are a convenience for explanatory purposesand not limiting.

Referring now to FIG. 13, at a first stage indicated by “a”, four sceneimages have been captured with the camera, as image pairs having bothlatent film images 214 and corresponding electronic images 216 in thememory. At stage “b”, in FIG. 13, an additional scene image has beencaptured as both an electronic image and a film image. In stage “c”, thefilm unit has been unloaded and replaced by a second film unit. Thisremoves the five latent images earlier captured, but leaves thecorresponding five electronic images. An additional sixth scene image iscaptured as an electronic image-latent image pair on the second filmunit. In the next stage, “d”, an additional scene image is captured asan electronic image and corresponding film image. This fills up to bememory of the camera to capacity. As a result, in stage “e”, when a newscene image is captured as a latent film image and correspondingelectronic image, the earliest electronic image stored in memory isreplaced by the newly captured electronic image of the final electronicimage-latent image pair. The absence of the earlier image is indicatedby an “X” bearing reference numeral 218. This is repeated in the finalstage, “f”.

Referring now to FIG. 14, in stage “a”, initially presented are fourlatent images and corresponding electronic images. Following the fourpairs of images is an electronic image without a corresponding latentfilm image. Another such electronic image without corresponding latentimage is captured in stage “b”. In stage “c”, a new image pair iscaptured. This fills of the capacity of the film units and,incidentally, also completely fills the capacity of memory withelectronic images. Therefore, in the next stage, “d”, when another sceneimage scene image is captured as both a latent image and an electronicimage, the earliest electronic image previously stored in memory isreplaced. This is repeated in stage “e”. In stage “f”, an electronicimage is captured “solely”, that is, without a corresponding latent filmimage, and the earliest electronic image in memory is again replaced.

Referring now to FIG. 15, at stage “a”, the first image pair captured isfollowed by a solely electronic capture followed by two more imagepairs, two more solely electronic captures, and another image pair. Instage “a”, the film unit has four latent images, but the memory isfilled to capacity with seven electronic images. In stage “b”, anothersolely electronic image is captured. The electronic image replaced isthe earliest electronic image that does not have a corresponding latentimage in the camera. In stage “c”, an image pair is captured and againthe earliest electronic image not having a corresponding latent filmimage in the camera is replaced. This fills the film units with fivelatent images. In stage “d”, the first film unit is replaced by a secondfilm unit and another image pair is captured. The electronic imagereplaced is the earliest that lacks a corresponding film image in a filmunit loaded in the camera. With the replacement of the film unit, all ofthe electronic images save the last, no longer have corresponding latentimages. In stage “e”, another solely electronic image is captured andthe earliest electronic image in memory is replaced. This is repeatedfor capture an image pair in stage “f”.

In FIG. 16, at stage “a”, seven electronic images are in memory andthree of them have corresponding latent images in the film unit. Instage “b”, an additional electronic image is captured replacing theearliest electronic image. In stage “c”, this is repeated. In stage is“d” and “e”, two image pairs are captured and the two earliestelectronic images are replaced. In stage “f”, the filled film unit isreplaced by a second film unit and a new image pair is captured.

The invention has been described in detail with particular reference tocertain preferred embodiments thereof, but it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention.

1. A method for managing electronic images in a hybrid electronic-filmcamera, said camera having memory for storing electronic images, saidmemory having an image capacity equal to a known number of electronicimages of a nominal size, said method comprising: loading a first filmunit in the camera, said first film unit having a first quantity ofavailable film frames, said first quantity being less than said imagecapacity; determining said first quantity; setting a tag number that isan integer value equal to or less than the difference between said imagecapacity and said first quantity; capturing a plurality of electronicimages in said camera; storing said electronic images in said memory;selectively assigning individual tags to one or more of said electronicimages to provide tagged images; removing said first film unit; loadinga second film unit in said camera, said second film unit having a secondquantity of available film frames, said second quantity being less thansaid image capacity; determining said second quantity; resetting saidtag number to an integer value that is equal to or less than thedifference between said image capacity and said second quantity; anddisplaying a warning when said tag number is less than the number ofsaid tagged images.
 2. The method of claim 1 further comprisingdetermining said number of said tagged images prior to said storing ofeach of said electronic images.
 3. The method of claim 1 wherein saidcapturing is further characterized as capturing a first plurality ofelectronic images prior to said removing and said storing is furthercharacterized as storing said first plurality of electronic images priorto said removing.
 4. The method of claim 3 further comprising: capturinga second plurality of electronic images in said camera, following saidloading of said second film unit; storing said second plurality ofelectronic images in said memory; and replacing one or more of saidtagged images during said storing.
 5. The method of claim 4 wherein saidresetting reduces said tag number.
 6. The method of claim 4 wherein saidassigning defines both said tagged images having said tags and one ormore untagged images lacking said tags and said method further comprisesreplacing said untagged images in said memory prior to said replacing ofsaid tagged images.
 7. The method of claim 6 wherein said steps ofreplacing said untagged and tagged images are each independently on afirst in-first out basis.
 8. The method of claim 4 further comprisingcapturing a first plurality of latent images in said first film unitduring said capturing of said first plurality of electronic images andcapturing a second plurality of latent images in said second film unitduring said capturing of said second plurality of electronic images,said latent images corresponding to respective said electronic images.9. The method of claim 4 wherein said displaying of said warning isprior to said replacing of said tagged images.
 10. The method of claim 1further comprising capturing a plurality of latent images on said firstfilm unit, said latent images corresponding to respective saidelectronic images.
 11. A method for managing electronic images in ahybrid electronic-film camera, said method comprising: loading a firstfilm unit in the camera, said first film unit having a first quantity ofavailable film frames; determining said first quantity; setting a tagnumber to an integer that is less than a preset maximum number;capturing a plurality of electronic images in said camera; storing saidelectronic images in said memory; selectively assigning individual tagsto one or more of said electronic images to provide tagged images;removing said first film unit; loading a second film unit in saidcamera, said second film unit having a second quantity of available filmframes; determining said second quantity; resetting said tag number toan integer that is less than said maximum number; and displaying awarning when said tag number is less than the number of said taggedimages.
 12. The method of claim 11 wherein said maximum number is lessthan said first and second quantities.
 13. A method for managingelectronic images in a hybrid electronic-film camera, said methodcomprising: loading a first film unit in the camera, said first filmunit having a first quantity of available film frames; determining saidfirst quantity of available film frames; setting a number of tags, saidsum of said number of tags plus said first quantity defining anelectronic image capacity; capturing a first plurality of electronicimages in said camera; storing said first plurality of electronic imagesin memory in said camera; selectively assigning individual said tags toone or more of said first plurality of electronic images to define oneor more tagged images having said tags and one or more untagged imageslacking said tags; totaling said tagged images to provide a total numberof said tagged images; removing said first film unit; loading a secondfilm unit in said camera, said second film unit having a second quantityof available film frames; determining said second quantity of availablefilm frames; resetting said number of said tags such that said sum ofsaid number of tags plus said second quantity equals said electronicimage capacity; and displaying a warning when said number of said tagsis less than said total number of said tagged images.
 14. The method ofclaim 13 further comprising the steps of: capturing a second pluralityof electronic images in said camera, following said loading of saidsecond film unit; replacing said untagged images in said memory withsome of said second plurality of electronic images; and following saidreplacing of said untagged images, replacing said tagged images withothers of said second plurality of electronic images.
 15. The method ofclaim 14 wherein said steps of replacing said untagged and tagged imagesare each independently on a first in-first out basis.
 16. The method ofclaim 15 further comprising capturing a first plurality of latent imagesin said first film unit during said capturing of said first plurality ofelectronic images and capturing a second plurality of latent images insaid second film unit during said capturing of said second plurality ofelectronic images, said latent images corresponding to respective saidelectronic images.
 17. The method of claim 15 wherein said secondquantity of available film frames being greater than said first quantityof available film frames.
 18. A method for managing electronic images ina hybrid electronic-film camera having memory with a known number ofelectronic image spaces, said method comprising: loading a first filmunit in the camera; detecting a number of available film frames in saidfirst film unit; setting a number of tags to the difference between saidnumber of electronic image spaces and said number of available filmframes of said first film unit; capturing a first plurality ofelectronic images in said camera; storing said first plurality ofelectronic images in said memory; selectively assigning each of saidtags to individual ones of said first plurality of electronic images todefine tagged images having said tags and untagged images lacking saidtags; unloading said first film unit; loading a second film unitfollowing said unloading; detecting the number of available film framesin said second film unit; resetting said number of tags to thedifference between said number of electronic image spaces and saidnumber of available film frames of said second film unit; capturing asecond plurality of electronic images in said camera; replacing saiduntagged images in said memory, on a first in-first out basis, with aninitial portion of said second plurality of electronic images; followingsaid replacing of said untagged images, replacing said tagged images insaid memory, on a first in-first out basis, with a final portion of saidsecond plurality of electronic images; and displaying a warning prior tosaid replacing of said tagged images.
 19. The method of claim 18 furthercomprising capturing corresponding latent images in respective said filmunits during said capturing steps.
 20. A hybrid electronic-film camerafor use with photographic film units, said film units each having anindicator of available film frames, said camera comprising: a bodyhaving a film holder sequentially loadable with said film units; a filmcapture unit adjoining said film holder, said film capture unit beingcapable of selectively capturing a plurality of latent images in saidfilm units; a reader disposed in operative relation to said film holderto read said indicators of said film units in said film holder; anelectronic capture unit disposed in said body, said electronic captureunit being capable of selectively capturing a series of electronicimages; memory disposed in said body in operative relation to saidelectronic capture unit, said memory storing said electronic images; atag selector disposed on said body, said tag selector selectivelyassigning a tag to one or more of said electronic images in said memory,said assigning defining said electronic images in said memory as taggedimages having one of said tags and untagged images lacking one of saidtags; and a controller operatively connected to said memory, saidreader, and said tag selector, said controller, during said capturing,blocking replacement of said tagged images and allowing replacement ofsaid untagged images, said controller setting a number of said tagsresponsive to each said reading of said indicator, said controllercalculating a running total of said tagged images, said controllergenerating a warning when said running total is greater than said numberof said tags.
 21. The camera of claim 20 further comprising a displaymounted on said body, said display showing said warning.